Biology: Reproduction Grade 9 Science

Sexual Reproduction 305-03 Compare sexual and asexual reproduction in terms of their advantages and disadvantages

Sexual Reproduction Sexual reproduction is reproduction where genetic material (DNA) ___________ Sexual reproduction requires the production of ___________ When male and female gametes combine it is called ___________ Gametes are created through ___________

Meiosis Meiosis is important to genetic variation It is a process where cells are created with a half set of DNA Normal body cells are ___________ ___________ : Cells that contain duplicate genes (46 chromosomes) Gametes are ___________ ___________ : cells that contain a single set of genes (23 chromosomes)

Meiosis Meiosis happens in 2 separate events: Meiosis I and Meiosis II Each one has its own prophase (I/II), metaphase (I/II), anaphase (I/II) and telophase (I/II)

Meiosis At the end of meiosis I, there are ___________ At the end of meiosis II, there are ___________

Video https://www.youtube.com/watch?v=qCLmR9-YY7o

Questions 1 How are the following pairs similar or different: asexual and sexual reproduction; body cells and gametes; haploid and diploid What is the main difference between mitosis and meiosis? Are muscle cells haploid or diploid? Explain. An organism has 5 pair of chromosomes. If a body cell undergoes mitosis, haw many cells are formed and how many chromosomes are inside? How many chromosomes would be in a sperm cell for this organism?

Sexual Reproduction in Plants Different classes of plant reproduce in different ways In every case a seed is produced that contains ___________ Sometimes the seed is protected in a cone or fruit or nut

Angiosperms ___________ are angiosperms Angiosperms produce flowers and or fruit Flowers contain reproductive organs, the ___________(female) and the ___________(male)

Gymnosperms Similar to angiosperms but no flowers or fruit Most produce seeds inside of cones ___________ separate trees In both angio- and gymnosperms seed ___________

Flower Lab

Animals Sexual reproduction in animals involves male and female gametes in the form of ___________(F) Sperm and eggs are ___________ When M and F gametes meet, fertilization happens A ___________ becomes a diploid cell ___________ Cells of a zygote ___________ to become an embryo

External Fertilization Fertilization where M and F gametes meet outside of the bodies of the parents Most common in ___________ This has some advantages: ___________ but still has genetic diversity Disadvantages: gametes can be wasted because they never find a gamete to be paired with

Internal Fertilization Fertilization where the gametes meet in the body of the female This includes egg-laying animals Advantage: ___________ Disadvantage: death of parents usually means the death of the offspring, more energy used finding a mate

What do you think? Talk with the people in your groups What are 2 advantages and 2 disadvantages to sexual reproduction?

Advantages of Sexual Reproduction Offspring has ___________(better adapted) Increased genetic variety ___________ Overtime ensures better ___________ of a species 2 parents to care for offspring

Disadvantages of Sexual Reproduction ___________ finding an acceptable partner ___________ of gametes is unpredictable More opportunity for mutations ___________ of a species lost because organisms are unable to find a mate

Questions 2 How does mitosis help create a variety of offspring? What is fertilization? Which animal would release more gametes and why: a frog or sea anemone Which animal would have more newly hatched young and why: a turtle or a bird

Please prepare a response to be handed in… The desert is a harsh environment, and it is difficult to survive. There are many challenges faced by the organisms that live there: Heat, finding food and water, reproduction… Which form of reproduction would be more beneficial for an organism, sexual or asexual? Please explain your answer in detail, using everything you know about reproduction. (Approximately 200 words)